<?phpclass Group extends AppModel{    	var $actsAs = array('Acl' => array('type' => 'requester'));	var $hasMany = 'User';   function parentNode()  {    if (!$this->id)    {      return null;    }     $data = $this->read();     if(!$data['Group']['parent_id'])    {      return null;    }     return array(      'model' => 'Group',      'foreign_key' => $data['Group']['parent_id']    );  }}?>